The multiple-point ignition combustion engine disclosed in Japanese Laid Open Application No. H04-183925 strives to provide combustion stability by arranging ignition plugs. The arrangement of the ignition plugs is determined based on the intensity of the swirl generated, the distribution of the mixture rate, and the distribution of the remaining gas.
However, even if the ignition plugs are arranged as described above, there is still room to further reduce emissions, such as hydrocarbons HC, etc., in the exhaust. In particular, there is a large amount of room for improvement for an engine that generates squish.